title: [Selection of laboratory rats for fertility components in synchronized estrus using Suisynchron-Praemix. 2. Results of litter development].
abstract: The following results were obtained from experimental studies into selection of laboratory rats for fertility and random mating with oestrus being synchronised by means of Suisynchron-Prämix, through eight generations: --Success of selection without synchronised oestrus was higher than that with synchronised oestrus by selection according to the basic index and with one and the same selection intensity. --Litter size and weight were higher in the selected variants, as a result of increased potential fertility (rate of ovulation). --In the population with selection and synchronised oestrus a negative relationship was found to exist between the directly correlated selection results regarding fertility parameters, on the one hand, and the effect of synchronisation, on the other. --Both the rates of ovulation and litter parameters were lower in the population with selection and synchronised oestrus, as a result of synchronisation. --The effect of synchronised oestrus on the population with selection and synchronised oestrus was partially eliminated owing to selection for fertility.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D004971:Estrus / Q000187:drug effects; D004973:Estrus Synchronization; D005260:Female; D005298:Fertility; D008098:Litter Size; D008297:Male; D008693:Methallibure / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D012641:Selection, Genetic; D013890:Thiourea / Q000031:analogs & derivatives*
chemical_list: D013890:Thiourea; D008693:Methallibure
vernacular_title: Selektion auf Komponenten der Fruchtbarkeit bei der Laboratoriumsratte unter den Bedingungen der Brunstsynchronisation mit Suisynchron-Prämix. 2. Mitteilung: Ergebnisse der Wurfentwicklung.